An image forming apparatus matches an image formed by an image forming unit with a fed and conveyed sheet in the width direction and performs an image forming process. A sheet conveyance path in the image forming apparatus and a conveyance path of a finisher, as an option, connected thereto are required to be matched with each other in the sheet width direction. A sheet cassette includes an adjustment mechanism by which the user adjusts the center position in the sheet width direction.
The sheet cassette includes for example two side walls to slide through a pinion gear and to regulate both sides of a sheet. A pinion holder rotatably holds the pinion. The pinion holder regulates the position of the sheet cassette with respect to a housing in the sheet width direction. The user adjusts the position of the pinion holder, and fixes the pinion holder to the housing by a screw or the like.
When the user strongly inserts the sheet cassette into the image forming apparatus, an impact force is transmitted to the pinion gear. There is a possibility that the position of the pinion gear is displaced in an adjustable area.
When the position of the pinion gear is displaced, the center position of the sheet stacked on the sheet cassette in the width direction varies from the initial position. In the image forming apparatus, the accuracy of the print position with respect to the sheet is degraded or the sheet is caught during conveyance and a jam can occur. However, before the abnormality as stated above occurs in the image forming process, the user can not easily recognize that the position of the pinion gear is displaced by some influence.